avoiding child death by size limit

Hi,

I have a problem where a mod_perl handler will allocate a lot of
memory when processing a request, and this causes Apache to kill the
child due to exceeding the configure child size limit.

However, the memory allocated will get freed up or re-used by the next
request - I think the memory is just fragmented enough to be
automatically reclaimed by the memory allocator (I've heard that some
mallocs can return memory to the OS in 1 MB chunks.)

Are there any special techniques people use to avoid this situation?
Does SizeLimit count actual memory used or does it just look at the
process size?

Thanks,
ER